From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 072EAC43381 for ; Thu, 28 Mar 2019 14:00:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D5C8E2173C for ; Thu, 28 Mar 2019 14:00:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726185AbfC1OA3 (ORCPT ); Thu, 28 Mar 2019 10:00:29 -0400 Received: from mx2.suse.de ([195.135.220.15]:33756 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725939AbfC1OA2 (ORCPT ); Thu, 28 Mar 2019 10:00:28 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 14571BB75; Thu, 28 Mar 2019 14:00:27 +0000 (UTC) Subject: Re: [PATCh v2 8/9] btrfs: tree-checker: Verify inode item To: dsterba@suse.cz, Qu Wenruo , linux-btrfs@vger.kernel.org, Nikolay Borisov References: <20190320063717.31770-1-wqu@suse.com> <20190320063717.31770-9-wqu@suse.com> <20190328133806.GD29086@twin.jikos.cz> <20190328135714.GF29086@twin.jikos.cz> From: Qu Wenruo Openpgp: preference=signencrypt Autocrypt: addr=wqu@suse.de; prefer-encrypt=mutual; keydata= mQENBFnVga8BCACyhFP3ExcTIuB73jDIBA/vSoYcTyysFQzPvez64TUSCv1SgXEByR7fju3o 8RfaWuHCnkkea5luuTZMqfgTXrun2dqNVYDNOV6RIVrc4YuG20yhC1epnV55fJCThqij0MRL 1NxPKXIlEdHvN0Kov3CtWA+R1iNN0RCeVun7rmOrrjBK573aWC5sgP7YsBOLK79H3tmUtz6b 9Imuj0ZyEsa76Xg9PX9Hn2myKj1hfWGS+5og9Va4hrwQC8ipjXik6NKR5GDV+hOZkktU81G5 gkQtGB9jOAYRs86QG/b7PtIlbd3+pppT0gaS+wvwMs8cuNG+Pu6KO1oC4jgdseFLu7NpABEB AAG0F1F1IFdlbnJ1byA8d3F1QHN1c2UuZGU+iQFUBBMBCAA+AhsDBQsJCAcCBhUICQoLAgQW AgMBAh4BAheAFiEELd9y5aWlW6idqkLhwj2R86El/qgFAlnVgp0FCQlmAm4ACgkQwj2R86El /qilmgf/cUq9kFQo577ku5gc6rFpVg68ublBwjYpwjw0b//xo+Wo1wm+RRbUGs+djSZAqw12 D4F3r0mBTI7abUCNWAbFkYZSAIFVi0DMkjypIVS7PSaEt04rM9VBTToE+YqU6WENeJ57R2p2 +hI0wZrBwxObdsdaOtxWtsp3bmhIbdqxSKrtXuRawy4KnQYcLuGzOce9okdlbAE0W3KHm1gQ oNAe6FX8nC9qo14m8LqEbThYH+qj4iCMlN8HIfbSx4F3e7nHZ+UAMW+E/lnMRkIB9Df+JyVd /NlXzIjZAggcWsqpx6D4wyAuexKWkiGQeUeArUNihAwXjmyqWPGmjVyIh+oC6LkBDQRZ1YGv AQgAqlPrYeBLMv3PAZ75YhQIwH6c4SNcB++hQ9TCT5gIQNw51+SQzkXIGgmzxMIS49cZcE4K Xk/kHw5hieQeQZa60BWVRNXwoRI4ib8okgDuMkD5Kz1WEyO149+BZ7HD4/yK0VFJGuvDJR8T 7RZwB69uVSLjkuNZZmCmDcDzS0c/SJOg5nkxt1iTtgUETb1wNKV6yR9XzRkrEW/qShChyrS9 fNN8e9c0MQsC4fsyz9Ylx1TOY/IF/c6rqYoEEfwnpdlz0uOM1nA1vK+wdKtXluCa79MdfaeD /dt76Kp/o6CAKLLcjU1Iwnkq1HSrYfY3HZWpvV9g84gPwxwxX0uXquHxLwARAQABiQE8BBgB CAAmFiEELd9y5aWlW6idqkLhwj2R86El/qgFAlnVga8CGwwFCQPCZwAACgkQwj2R86El/qgN 8Qf+M0vM2Idwm5txZZSs+/kSgcPxEwYmxUinnUJGyc0ZWYQXPl0cBetZon9El0naijGzNWvf HxIPB+ZFehk6Otgc78p1a3/xck/s1myFRLrmbbTJNoFiyL25ljcq0J8z5Zp4yuABL2RiLdaZ Pt/jfwjBHwGR+QKp6dD2qMrUWf9b7TFzYDMZXzZ2/eoIgtyjEelNBPrIgOFe24iKMjaGjd97 fJuRcBMHdhUAxvXQF1oRtd83JvYJ5OtwTd8MgkEfl+fo7HwWkuHbzc70L4fFKv2BowqFdaHy mId1ijGPGr46tuZ5a4cw/zbaPYx6fJ4sK9tSv/6V1QPNUdqml6hm6pfs6A== Message-ID: <70209af7-5948-4bfc-a3a0-06a258ad8ed9@suse.de> Date: Thu, 28 Mar 2019 22:00:22 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.5.3 MIME-Version: 1.0 In-Reply-To: <20190328135714.GF29086@twin.jikos.cz> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On 2019/3/28 下午9:57, David Sterba wrote: > On Thu, Mar 28, 2019 at 09:42:59PM +0800, Qu Wenruo wrote: >> >> >> On 2019/3/28 下午9:38, David Sterba wrote: >>> On Wed, Mar 20, 2019 at 02:37:16PM +0800, Qu Wenruo wrote: >>>> + if (S_ISDIR(mode) && btrfs_inode_nlink(leaf, iitem) > 1) { >>>> + inode_item_err(fs_info, leaf, slot, >>>> + "invalid nlink: has %u expect no more than 1 for dir", >>>> + btrfs_inode_nlink(leaf, iitem)); >>>> + goto error; >>>> + } >>> >>> I'm not sure about this check, the number of links for a directory is 1, >>> but the exact count could be implemented (there's a project idea for >>> that). I don't know if this will require an incompat bit or not. >> >> That means we have hard link for directories. > > Yes, hard links of directories are forbidden by VFS but that's not the > point here: > > https://btrfs.wiki.kernel.org/index.php/Project_ideas#Track_link_count_for_directories > > "The link count for directories is traditionally used to count the number > of subdirectores iff the link count is >= 2." Oh, got it. But for that case, it would be much better to go for things like nbytes or size, as by all means, those two members are less meaningful than nlinks for directory. Thanks, Qu >